G.M. Kiebert

The impact of breast-conserving treatment and mastectomy on the quality of life of early-stage breast cancer patients: a review.

In recent years, doubt has been shed on the necessity of mastectomy for women with early-stage breast cancer. Apart from purely medical studies comparing (radical) mastectomy to less intruding surgical treatment, a number of studies (N = 18) have been published investigating the impact of breast-conserving treatment versus mastectomy on quality of life. We review these studies with respect to medical issues (treatment modality, stage of disease), methodologic issues (design, measurement moment, sample size), and results (psychologic discomfort, changes in life patterns, fears and concerns). It is concluded that there is no solid proof of a better psychologic adjustment after breast-conserving treatment and that there are no substantial differences between the different treatment modalities in changes of life patterns and fears and concerns. However, the results with respect to body image and sexual functioning favor the use of breast-conserving treatment.

Utility assessment in cancer patients : adjustment of time tradeoff scores for the utility of life years and comparison with standard gamble scores

The standard gamble (SG) and the time tradeoff (TTO), two frequently used methods of utility assessment, have often been found to lead to different utilities for the same health state. The authors investigated whether adjustment of TTO scores for the utility of life years (risk attitude) eliminated this difference. In addition, the association between risk attitude and sociodemographic and medical variables was studied. In 30 disease-free testicular cancer patients, SG and TTO were used to assess the utilities of four health profiles relevant to testicular cancer. Utility of life years was estimated from certainty equivalents (CEs). SG scores were significantly higher than unadjusted TTO scores for all profiles. As the majority of patients (85%) were risk-averse, CE-adjusted TTO scores were higher than unadjusted scores, and were not significantly different from those obtained from the SG for three of the four profiles. However, adjusted scores were still slightly but consistently lower than SG scores. Possible explanations for this discrepancy are discussed. An association was found between risk aversion and medical treatment: patients who had received chemotherapy for their cancers were more risk-averse than were patients who had been in a surveillance protocol only. As risk aversion can have an impact on treatment decisions, it is important to assess the risk posture of the patient to whom the decision pertains. Key words: utility assessment; QALY; risk aversion; oncology; treatment preferences. (Med Decis Making 1994;14:82-90)

The “utility” of the time trade-off method in cancer patients: Feasibility and proportional trade-off

We examined the feasibility and the proportional trade-off assumption of the Time Trade-Off method. Utilities were assessed of the actual health states of 54 testicular and 72 colorectal cancer patients, treated with the curative intent and 29 incurable colorectal cancer patients. Three periods of time were used to assess proportionality: the subjects life expectancy and two shorter periods. Results showed the method to be feasible in curatively treated patients, though the use of life expectancy posed difficulties in some very old subjects. This same difficulty was encountered in patients with symptomatic incurable disease. A two step procedure is proposed as a solution. The proportional trade-off assumption was violated. Utilities for the longer period were smaller than those for the shorter periods. Life expectancy and trade-off did not correlate, though. Remarkable was that many patients were unwilling to trade at all. The implications of the findings are discussed.

The 'utility' of the visual analog scale in medical decision making and technology assessment. Is it an alternative to the time trade-off?

Methods often used for the valuation of health states are the time trade-off (TTO) and the visual analog scale (VAS). The VAS is easier than the TTO and can be self-administered; however it usually leads to lower scores. In the literature a power transformation of group mean VAS scores to TTO scores has been proposed. We were able to replicate this finding of a power function. We found coefficients that were very similar to those from the literature, for 183 cancer patients. The relationship existed independently of disease state and health status.

Choices in oncology: factors that influence patients' treatment preference

Medical treatment of cancer often entails a trade-off between outcomes of two different attributes: quality of life (QOL) and length of life (LL). This process of weighing advantages and disadvantages seems to be influenced by different factors. The main purposes of this study were (a) to investigate the relative importance of different factors on the trade-off and (b) to explore the relationship between these importance ratings and personal characteristics. We asked 199 patients with cancer to indicate to what degree they consider a number of factors to be of importance if they had to choose between two treatment modallties that differ in their expected outcomes concerning QOL and LL. The seven factors were their age at the time of decision, having a partner, having children, inability to work due to side-effects of the treatment, the nature of the side-effects, disease-related life expectancy and baseline QOL. The results indicate that six of the seven factors were of considerable to great importance when a treatment choice had to be made. The negative effects of treatment on the ability to work did not seem to be a very important consideration. Patient age and education were positively associated with importance ratings.

Effect of peri-operative chemotherapy on the quality of life of patients with early breast cancer

Since chemotherapy is assumed to have a negative impact on quality of life, the impact of peri-operative chemotherapy on physical, psychological and social well-being and on the activity level of patients with early stage breast cancer was investigated. 24 women received peri-operative chemotherapy and 29 did not. They were interviewed 2 months and at a mean of 12 months post-surgery. Although the treated group reported more fatigue and considered hair loss a severe side-effect, no differences were found in overall physical and physiological well-being, perceived social interaction and activity level at 2 months. 1 year after surgery no differences were found between the two groups. Although no substantial effects of peri-operative chemotherapy on quality of life were demonstrated, patients almost unanimously considered peri-operative chemotherapy the most burdensome aspect of the treatment because of alopecia.

Test-retest reliabilities of two treatment-preference instruments in measuring utilities

The authors assessed the test-retest reliabilities of two treatment-preference instruments recently applied to the measurement of the utilities of health states after different treatment modalities for cancer. The first instrument measures the strengths of preferences concerning a choice between a wait-and-see policy, and treatment with radiotherapy after an initial surgical breast-conserving procedure for early breast cancer. The second measures the strengths of preferences concerning a choice between two hypothetical surgical treatment outcomes in cancer of the rectum with different probabilities of expected five-year survival. Both measure the strength of a subjects treatment preference given probabilities of treat ment-related costs and benefits. The subjects were radiotherapy technicians (n = 20) and cancer patients (n = 20) who were interviewed in weeks 2 and 4 of radiotherapy. The test- retest reliabilities of both instruments were inconsistent and moderately high, with Spear- mans rank correlations ranging from 0.38 to 0.81 and weighted kappas ranging from 0.38 to 0.69. To investigate whether the start of treatment with radiotherapy influenced the utilities that patients assigned to health states, the same procedure was applied in another, com parable, group of patients with cancer (n = 20). For this group, the first assessment was made prior to the start of treatment and the second during the second week of radiation therapy. The scores of this group of patients indeed appeared to be less stable than the scores of the patients assessed in weeks 2 and 4 of radiotherapy. However, the instability of the scores could have been the result of test bias. Key words: test-retest reliability; utility assessment; oncology. (Med Decis Making 1993;13:133-140)